Apparatuses for processing additive manufactured objects and methods of use

ABSTRACT

An apparatus (200) for smoothing a surface of an object (100). The apparatus includes a chamber (210), a reservoir (324) configured to hold a liquid (322), and a nebulizer assembly (212) configured to generate a mist (104) from the liquid into the chamber. The nebulizer assembly includes a mesh (732), a vibrating element (731), and a wick (736). The object is received in the chamber and the mist is configured to surround the object.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/736,702, filed Dec. 14, 2017, which is a National Stage Applicationunder 35 U.S.C. § 371 of International Application No.PCT/CN2016/080225, filed Apr. 26, 2016, which claims priority to andbenefits of International Patent Application No. PCT/CN2015/081512,filed Jun. 16, 2015, all of which are incorporated herein by referencein its entirety their entireties.

TECHNICAL FIELD

Embodiments of the present disclosure are directed to methods andapparatuses for processing objects, and more particularly, to methodsand apparatuses for processing objects created using additivemanufacturing processes.

BACKGROUND OF THE DISCLOSURE

Additive manufacturing is any of various manufacturing technologies thatbuild objects in an additive, typically layer-by-layer, fashion.Additive manufacturing is also referred to by the general public as “3Dprinting”. One type of the additive manufacturing technologies is basedon extrusion deposition, such as fused deposition modeling® (FDM®) orfused filament fabrication (FFF). Over the last few years FDM® or FFFhas become a commonly used technology for modeling, prototyping, andproduction applications.

FDM® or FFF generally involve feeding a thermoplastic polymer in theform of a continuous filament to a heated extrusion nozzle. Thethermoplastic polymer in the extrusion nozzle may be heated to atemperature above its glass transition temperature, at which thethermoplastic filament may become a viscous melt and therefore beextruded. The extrusion nozzle may be moved in a three-dimensionalmotion and precisely controlled by step motors and computer-aidedmanufacturing (CAM) software so that an object may be built from thebottom up, one layer at a time. The first layer of the object may bedeposited on a substrate and additional layers may be sequentiallydeposited and fused (or partially fused) to the previous layer bysolidification due to a drop in temperature. The process may continueuntil the three-dimensional object is fully constructed. This technologyis disclosed in, for example, U.S. Pat. No. 5,121,329.

An object created using an additive manufacturing process, such as FDM®or FFF, may have a series of grooves, ridges, and/or edges along thesurface where the thermoplastic filament is sequentially deposited andfused (or partially fused) onto the previous layer. This may result in asurface that has a rougher finish than what can be achieved using othermanufacturing methods, e.g., injection molding. The rougher finish hasseveral disadvantages. First, the objects created using the additivemanufacturing processes can be less aesthetically appealing compared tothose prepared using other manufacturing methods, such as injectionmolding. Second, a rougher surface finish can make it difficult to applyadditional surface finishing techniques, such as painting orelectroplating, to the objects. Additionally, the grooves, ridges,and/or edges on the surface of the objects may serve as stressconcentrators that may lead to reduced mechanical properties of theobjects.

Methods for reducing the roughness of the surface of an object madeusing additive manufacturing processes may include, for example, sandingor other techniques using abrasive materials to remove some of thethermoplastic filament at, for example, the ridges and edges. Many ofthe materials used in FDM® and FFF additive manufacturing processes haverelatively low softening temperatures. Such sanding can have adetrimental effect on the shape or features of the part created becauseof the substantial amount of heat that can be generated by friction.Another method for reducing the roughness of the surface of an objectmade using additive manufacturing processes is shot peening or shotblasting with some media. Both sanding and shot blasting requireextensive skills, labor, and time to effectively reduce the roughness ofthe surface of the object. Other methods involve exposing an object madeusing additive manufacturing processes to a solvent vapor generated byheating a reservoir of organic solvent. However, the organic solventvapor can be highly flammable and may have negative health effects onthe user exposed to the vapor. Additionally, the heated solvent vaporcan lead to macroscopic deformation of the object during the exposure.

Accordingly, there exists a need for methods and apparatuses to improvethe smoothness or reduce the roughness of the surface of objects, forexample, objects created using additive manufacturing processes.

SUMMARY OF THE DISCLOSURE

Embodiments of the present disclosure are directed to methods andapparatuses for processing additive manufactured objects Variousembodiments of the disclosure may include one or more of the followingaspects.

In accordance with one embodiment, an apparatus for smoothing a surfaceof an object may include a chamber a reservoir configured to hold aliquid, and a nebulizer assembly configured to generate a mist from theliquid into the chamber. The nebulizer assembly may include a mesh, avibrating element, and a wick. The object may be received in the chamberand the mist is configured to surround the object.

Various embodiments of the apparatus may include one or more of thefollowing features: the object may be made by an additive manufacturingtechnique using at least one thermoplastic polymer; the nebulizerassembly may further include a driver circuit electrically connected tothe vibrating element; the apparatus may further include controlcircuits; the control circuits may include a memory and a processingcircuit electrically connected to the driver circuit; the memory maystore a plurality of instructions for operation of the apparatus and/orthe nebulizer assembly, and the processing circuit may execute at leastone of the instructions and send electrical signals associated with theexecuted instructions to the driver circuit; the apparatus may furtherinclude a user control electrically connected to the control circuits;the mesh and the vibrating element of the nebulizer assembly may form anintegrated part; the apparatus may further include a plate between thechamber and the reservoir; the plate may have at least one openingand/or a concave surface configured to allow micro droplets of the mistto pass through; the apparatus may further include a rotatable platformand a motor configured to rotate the rotatable platform; the object maybe received on the rotatable platform; the nebulizer assembly mayfurther include a coupler placed between the vibrating element and thewick; the coupler may be configured to transport the liquid from thewick to the mesh with limited or minimized impact on movement of themesh caused by the vibrating element; the coupler and the wick of thenebulizer assembly may be one integrated part; the coupler and/or wickmay be made of a material that does not substantially dissolve in orreact with the liquid; the material of the coupler and/or wick mayinclude a plurality of pores and/or channels; the material of thecoupler and/or wick may be a soft, a compressible, a compliant, asquishy, a foam-like, a sponge, or a resiliency deformable material; themist may include micro droplets whose diameters range from 5 μm to 100μm; the apparatus may further include a plurality of light sourcesconfigured to illuminate the mist and/or the object; the apparatus mayfurther include an automatic or a manual lifting mechanism configured toraise the object out of the chamber and/or configured to lower theobject into the chamber; the apparatus may further include anair-agitating device configured to Increase movement of the air and/ormicro droplets of the mist in the chamber; the nebulizer assembly may beconfigured to generate a continuous, intermittent, or pulsatile mist, orcombinations thereof; the at least one thermoplastic polymer may beselected from vinyl acetal polymers, acrylonitrile-butadiene-styrene,poly (lactic acid), polycarbonate, polystyrene, high impact polystyrene,polycaprolactone, polyamide and polyamide copolymers, and cellulosebased polymers; the liquid may include at least one solvent selectedfrom alcohols, ethers, esters, and ketones.

In accordance with another embodiment, a method for smoothing a surfaceof an object may include receiving the object in a chamber, generating amist by a nebulizer assembly from a liquid held in a reservoir into thechamber, and surrounding the object with the mist. The nebulizerassembly may include a mesh, a vibrating element, and a wick.

Various embodiments of the method may include one or more of thefollowing features: the method may further Include making the object byan additive manufacturing technique using at least one thermoplasticpolymer; the nebulizer assembly may further include a driver circuitelectrically connected to the vibrating element; the method may furtherinclude operating the nebulizer assembly by control circuits comprisinga memory and a processing circuit electrically connected to the drivercircuit; the memory may store a plurality of instructions for theoperation of the nebulizer assembly; the processing circuit may executeat least one of the instructions and send electrical signals associatedwith the executed instructions to the driver circuit; the controlcircuits may be electrically connected to a user control; the mesh andthe vibrating element of the nebulizer assembly may form an integratedpart; there may be a plate located between the chamber and thereservoir; the plate may have at least one opening and/or a concavesurface configured to allow micro droplets of the mist to pass through;the method may further include rotating the rotatable platform by amotor; the object may be received on the rotatable platform; thenebulizer assembly may further include a coupler placed between thevibrating element and the wick; the coupler may be configured totransport the liquid from the wick to the mesh with limited or minimizedimpact on movement of the mesh caused by the vibrating element; thecoupler and the wick may be one integrated part; the coupler and/or thewick may be made of a material that does not substantially dissolve inor react with the liquid; the material may include a plurality of poresand/or channels; the material may be a soft, a compressible, acompliant, a squishy, a foam-like, a sponge, or a resiliency deformablematerial; the mist may include micro droplets whose diameters range from5 μm to 100 μm; the method may further include illuminating the mistand/or the object using a plurality of light sources; the method mayfurther include raising the object out of the chamber, and/or loweringthe object into the chamber using an automatic or a manual liftingmechanism; the method may further include increasing movement of the airand/or micro droplets of the mist in the chamber using an air-agitatingdevice; the method may further include generating by the nebulizerassembly a continuous, intermittent, or pulsatile mist, or combinationsthereof; the at least one thermoplastic polymer may be selected fromvinyl acetal polymers, acrylonitrile-butadiene-styrene, poly (lacticadd), polycarbonate, polystyrene, high impact polystyrene,polycaprolactone, polyamide and polyamide copolymers, and cellulosebased polymers; the liquid may include at least one solvent selectedfrom alcohols, ethers, esters, and ketones.

In accordance with another embodiment, an apparatus for smoothing asurface of an object may include a chamber, a reservoir configured tohold a liquid, a nebulizer assembly configured to generate a mist fromthe liquid into the chamber, and an air-agitating device. The object maybe placed in the chamber. The mist may be configured to substantiallyuniformly surrounding the object.

In accordance with another embodiment, a nebulizer assembly forgenerating a mist from a liquid may include a mesh, a vibrating element,a wick configured to absorb the liquid, and a coupler having a firstsurface contacting the mesh and/or the vibrating element, and a secondsurface contacting the wick. The coupler may be configured to transportthe liquid from the wick to the mesh with substantially limited impacton movement of the mesh caused by the vibrating element.

Objects created using additive manufacturing processes may be made withthermoplastic polymers, including composite materials with thermoplasticmatrices. Suitable additive manufacturing processes may include, but arenot limited to, material extrusion based techniques, such as FDM® andFFF, power bed fusion such as selective laser sintering (SLS), sheetlamination, binder jetting, and material jetting. In some embodiments,objects may be created by any suitable additive manufacturing technique,including those to be developed in the future that fall into the scopeof the term “additive manufacturing” known in the art.

Embodiments of the present disclosure are advantageous over previousmethods. One advantage is that heating of a liquid is not necessarilyrequired to generate a mist. The liquid, e.g., alcohols or alcoholsolutions, used in the methods and apparatuses disclosed herein aretypically benign in terms of toxicity, which reduces the health risk tousers of the methods and apparatuses disclosed herein. Further,distribution and/or density of the mist are substantially easier toobserve than organic solvent vapor so that detecting or observing a leakof the mist from an enclosed chamber can be much easier. Anotheradvantage is that the methods and apparatuses disclosed herein allow anamount of processing time ranging from about 10 to about 60 minutes tosubstantially reduce the roughness of the surface of the object or toachieve a satisfactory surface smoothness of the object. Additionally,methods and apparatuses disclosed herein may allow processing and/orsmoothing of more than one object at a time. Another advantage is thatthe methods and apparatuses disclosed herein may not change the overallshape and/or form of the object. The mist is generated from the liquidapproximately at room temperature without heating the liquid. This maylimit, prevent, or substantially reduce the deformation of the objectwhile being exposed to the mist. Finally, the methods and apparatusesdisclosed herein allow efficient generation of the mist from the liquidso that a small or minimal amount of liquid Is consumed to process oneor more objects.

The details of one or more variations of the present disclosure are setforth below and the accompanying drawings. Other features and advantagesof the present disclosure will be apparent from the detailed descriptionbelow and drawings, and from the claims.

Further modifications and alternative embodiments will be apparent tothose of ordinary skill in the art in view of the present disclosure.For example, the methods and apparatuses may include additionalcomponents or steps that are omitted from the diagrams and descriptionfor clarity of operation. Accordingly, the detailed description below isto be construed as illustrative only and is for the purpose of teachingthose skilled in the art the general manner of carrying out the presentdisclosure, it is to be understood that the various embodimentsdisclosed herein are to be taken as exemplary. Elements and materials,and arrangements of those elements and materials, may be substituted forthose illustrated and disclosed herein, parts and processes may bereversed, and certain features of the present disclosure may be utilizedindependently, all as would be apparent to one skilled in the art afterhaving the benefit of the disclosure herein. Changes may be made in theembodiments disclosed herein without departing from the spirit and scopeof the present disclosure and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates a perspective view of a surface of an exemplaryobject, according to embodiments of the present disclosure.

FIG. 1B illustrates a cross-sectional view of exemplary micro dropletsof a mist surrounding the surface of the object shown in FIG. 1A,according to embodiments of the present disclosure.

FIG. 1C illustrates a cross-sectional view of the surface of the objectshown in FIG. 1A after exposure to the micro droplets of the mist, asshown in FIG. 1B, according to embodiments of the present disclosure.

FIG. 1D illustrates a perspective view of the surface of the objectafter exposure to the micro droplets of the mist, as shown in FIG. 1Baccording to embodiments of the present disclosure.

FIG. 2 illustrates a cross-section of an exemplary apparatus, accordingto embodiments of the present disclosure.

FIG. 3A illustrates an exemplary nebulizer, according to embodiments ofthe present disclosure.

FIG. 3B illustrates an exemplary nebulizer, in accordance with thepresent disclosure.

FIG. 3C illustrates an exemplary nebulizer, according to embodiments ofthe present disclosure.

FIG. 4 is a schematic representation of the chemical structure of anexemplary polymer for making an object, according to embodiments of thepresent disclosure.

FIG. 5A illustrates a perspective view of an exemplary apparatus,according to embodiments of the present disclosure.

FIG. 5B illustrates a perspective view of an exemplary apparatus,according to embodiments of the present disclosure.

FIG. 5C illustrates a perspective view of a cross-section of anexemplary apparatus, according to embodiments of the present disclosure.

FIG. 6A illustrates a perspective view of an exemplary apparatus,according to embodiments of the present disclosure.

FIG. 6B illustrates a perspective view of a cross-section of anexemplary apparatus, according to embodiments of the present disclosure.

FIG. 7A illustrates a cross-section of an exemplary nebulizer, accordingto embodiments of the present disclosure.

FIG. 7B illustrates a perspective view of part of an exemplarynebulizer, according to embodiments of the present disclosure.

FIG. 8 illustrates an exploded view of an exemplary cartridge, accordingto embodiments of the present disclosure.

FIG. 9A illustrates a perspective view of an exemplary apparatus,according to embodiments of the present disclosure.

FIG. 9B illustrates a perspective view of a cross-section of anexemplary apparatus, according to embodiments of the present disclosure.

FIG. 9C illustrates a perspective view of a cross-sexton of an exemplaryapparatus, according to embodiments of the present disclosure.

FIG. 10A illustrates a perspective view of a lid of an exemplaryapparatus according to embodiments of the present disclosure.

FIG. 10B illustrates an exploded view of a lid of an exemplaryapparatus, according to embodiments of the present disclosure.

FIG. 10C illustrates a cross-section of a lid of an exemplary apparatus,according to embodiments of the present disclosure.

DETAILED DESCRIPTION

This description and the accompanying drawings that illustrate exemplaryembodiments should not be taken as limiting. Various mechanical,compositional, structural, electrical, and operational changes may bemade without departing from the scope of this description and theclaims, including equivalents. In some instances, well-known structuresand techniques have not been shown or described in detail so as not toobscure the disclosure. Similar reference numbers in two or more figuresrepresent the same or similar elements. Furthermore, elements and theirassociated features that are disclose in detail with reference to oneembodiment may, whenever practical, be included in other embodiments inwhich they are not specifically shown or described. For example, if anelement is described in detail with reference to one embodiment and isnot described with reference to a second embodiment, the element maynevertheless be claimed as included in the second embodiment.

For the purposes of this specification and appended claims, unlessotherwise indicated, all numbers expressing quantities, percentages, orproportions, and other numerical values used in the specification andclaims, are to be understood as being modified in all instances by theterm “about,” to the extent they are not already so modified.Accordingly, unless indicated to the contrary, the numerical parametersset forth in the following specification and attached claims areapproximations that may vary depending upon the desired propertiessought to be obtained. At the very least, and not as an attempt to limitthe application of the doctrine of equivalents to the scope of theclaims, each numerical parameter should at least be construed in lightof the number of reported significant digits and by applying ordinaryrounding techniques.

It is noted that, as used in this specification and the appended claims,the singular forms “a,” “an,” and “the,” and any singular use of anyword, include plural referents unless expressly and unequivocallylimited to one referent. As used herein, the term “include” and itsgrammatical variants are intended to be non-limiting, such thatrecitation of items in a list is not to the exclusion of other likeitems that can be substituted or added to the listed items.

Further, this description's terminology is not intended to limit theinvention. For example, spatially relative terms, such as “beneath”,“below”, “lower”, “above”, “upper”, “proximal”, “distal”, and the like,may be used to describe one element's or feature's relationship toanother element or feature as illustrated in the figures. Thesespatially relative terms are intended to encompass different positions(i.e., locations) and orientations (i.e., rotational placements) of adevice in use or operation in addition to the position and orientationshown in the figures. For example, if a device in the figures is turnedover, elements described as “below” or “beneath” other elements orfeatures would then be “above” or “over” the other elements or features.Thus, the exemplary term “below” can encompass both positions andorientations of above and below. A device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein may be interpreted accordingly.

Disclosed herein are methods and apparatuses for processing, an object,e.g., an object made using additive manufacturing processes. The methodsmay include processing an object using a mist generated from a liquid.As disclosed herein, a mist may refer to an aerosol and/or a collectionof small droplets, e.g., micro droplets, of a liquid suspended in air.The mist may interact with the surface of the object and may reduce theroughness or improve the smoothness of the surface of the object. Thisreduction in surface roughness or improvement in surface smoothness maybe referred to as “finishing”, “polishing,” or “smoothing” the object,and may create, after processing of the object using the methodsdisclosed herein, a surface that is more smooth and/or shiny, e.g.,reflecting more light, compared to the surface of the object prior tothe processing, e.g., polishing, smoothing, and/or finishing. Asdescribed herein, both roughness and smoothness may be used to describethe evenness and the texture of the surface of an object.

Additionally or alternatively, the methods may not produce asubstantially shiny surface after processing the object. In someembodiments, the methods for processing the object may cause a specificand/or desirable degree of roughness to the surface of the object. Thismay allow specific types of finishing steps to be applied to the surfaceof the object to achieve some desired attributes, such as colors. Suchfinishing steps may include, for example, painting, electroplating, orother suitable techniques that require a particular texture or roughnessof the surface of the object to maximize desired attributes created bythese finishing steps.

FIGS. 1A-1D illustrate an exemplary method for processing an object 100,e.g., an object made using an additive manufacturing process. Asdescribed herein, processing of object 100 may include increasing thesmoothness and/or reducing the roughness of the surface of object 100 toa suitable degree, and may be referred to as smoothing or polishingobject 100. FIG. 1A illustrates a perspective view of a surface 102 ofobject 100 before the processing. In some embodiments, a method forprocessing object 100 may include generating a mist 104 from a liquidand surrounding surface 102 of object 100 with mist 104. Mist 104 mayinclude micro droplets that may be suspended or distributed in air. Forexample, FIG. 1B illustrates a cross-sectional view of micro droplets ofmist 104 surrounding surface 102 of object 100. FIG. 1C illustrates across-sectional view of surface 102 of object 100 after being exposed tomist 104 or surrounded by the micro droplets of mist 104. In someembodiments, a method for processing object 100 may include allowingobject 100 to be exposed to mist 104 or surrounded by the micro dropletsof mist 104 for a predetermined amount of time. FIG. 1D illustrates aperspective view of surface 102 of object 100 after the processing.Methods for processing object 100 in accordance with the currentdisclosure may reduce the roughness, e.g., textures, grooves, edges,and/or ridges on surface 102 of object 100, and/or increase thesmoothness of surface 102 of object 100.

In some embodiments, object 100 may be manufactured using any suitableadditive manufacturing process. These additive manufacturing processesmay include, for example, material extrusion, binder jetting, materialjetting, sheet lamination, powder bed fusion, selective laser melting(SLM), direct metal laser sintering (DMLS), selective laser sintering(SLS), selective heat sintering (SHS), robocasting, stereolithography(SLA), laminated object manufacturing (LOM), digital light processing(DLP), plaster-based 3D printing (PP), electron-beam melting (EBM),electron beam freeform fabrication (EBF), and photopolymerization.

Object 100 may be made of a material suitable for an additivemanufacturing process, such as FDM® or FFF. For example, object 100 maybe made of a material selected from vinyl acetal polymers,acrylonitril-butadiene-styrene (ABS), poly(lactic acid) (PLA),polycarbonate (PC), polystyrene (PS), high impact polystyrene (HIPS),polycaprolactone (PCL), polyamide or polyamide copolymers, and cellulosebased polymers. In some embodiments, object 100 may be made of at leastone thermoplastic polymer selected from vinyl acetal polymers, polyamideor polyamide copolymers, and cellulose based polymers. The vinyl acetalpolymers may be selected from poly (vinyl butyral). In some embodiments,the poly (vinyl butyral) may include vinyl acetate, vinyl alcohol, andvinyl butyral monomeric units. In some embodiments, the poly (vinylbutyral) may include vinyl acetate monomeric units in an amount rangingfrom about 0% to about 1%, from about 0% to about 2%, from about 0% toabout 3%, from about 0% to about 4%, or from about 0% to about 5%, byweight. In some embodiments, the poly (vinyl butyral) may include vinylalcohol monomeric units in an amount ranging from about 10% to about30%, from about 15% to about 30%, from about 20% to about 30%, fromabout 10% to about 15%, or from about 10% to about 25%, by weight. Insome embodiments, the poly (vinyl butyral) may include vinyl butyralmonomeric units in an amount ranging from about 65% to about 90%, fromabout 65% to about 70%, from about 65% to about 80%, from about 70% toabout 80% from about 71% to about 85%, or from about 80% to about 90%,by weight.

The methods and apparatuses disclosed herein may be applied to objectsmade with any suitable manufacturing process as long as the materialused for making the objects is a thermoplastic polymer, for example, acomposite material having a thermoplastic polymer matrix.

FIG. 2 illustrates an exemplary apparatus 200 for processing object 100.Apparatus 200 may include a first chamber 210 that may provide anenclosed and/or sealed space for processing object 100. Apparatus 200may include a second chamber 216. Chamber 216 may be used to store orhold a liquid 322. Apparatus 200 may include a nebulizer 212 that isused to generate the micro droplets of mist 104 from liquid 322.Apparatus 200 may include a user control 211 and control circuits 217.User control 211 and/or control circuits 217 may be used to adjust andcontrol apparatus 200, e.g., adjust or control nebulizer 212.

In some embodiments, apparatus 200 may include a rotatable platform 213and a rotational motor 220. Rotational motor 220 may be electricallyconnected to control circuits 217 and may be controlled or adjusted byuser control 211 and/or control circuits 217. Object 100 may beremovably received on rotatable platform 213. During the processing ofobject 100, mist 104 generated by nebulizer 212 may surround object 100placed on rotatable platform 213 inside chamber 210, as shown in FIG. 2, and object 100 may rotate in the same rotational motion as rotatableplatform 213.

In some embodiments, apparatus 200 may include a porous membrane 215.Porous membrane 215 may be located between chamber 210 and chamber 216,and may allow the micro droplets of mist 104 in chamber 210 to pass,such as flow, diffuse, and/or disperse, through into chamber 216. Theporous membrane 215 may be made of any suitable material whose poresizes allow the micro droplets of mist 104 or a collection of the microdroplets that do not coat or interact with object 100 to pass through.

Increasing the uniformity and/or evenness of the micro droplets of mist104 surrounding object 100 may increase the evenness and/or uniformityof the exposure of object 100 to the micro droplets, and thus mayincrease the uniformity and/or evenness of the smoothing of the surfaceof object 100. For example, rotatable platform 213 may allow object 100to rotate while being surrounded by mist 104. The rotation of object 100may allow different locations and/or sides of object 100 to besubstantially similarly exposed to mist 104, and thus may allow thedifferent locations and/or sides of object 100 to have substantiallyuniform degree of smoothness after the processing.

Although FIG. 2 shows one nebulizer 212, in some embodiments, more thanone nebulizer 212 may be included in apparatus 200 to increase thevolume and/or density of mist 104 in chamber 210. Although FIG. 2 showsnebulizer 212 located inside chamber 210, in some embodiments, nebulizer212 may also be located outside of chamber 210. In such embodiments, themicro droplets of mist 104 may be transported from an external nebulizer212 into chamber 210 through an opening and/or a conduit.

Liquid 322 may be selected based on the material used to manufactureobject 100. Liquid 322 may substantially dissolve or partially dissolvethe material of object 100. In some embodiments, liquid 322 may includea solvent. As disclosed herein, a solvent may refer to any substancethat may dissolve a solute, i.e., a chemically different liquid, solid,or gas, resulting in a solution. Examples of a suitable liquid 322 mayinclude, but are not limited to, organic solvents, such as alcohols(e.g., methanol, ethanol, isopropanol, n-propanol, isobutanol, butanol,neopentyl alcohol), ethers (e.g., diethyl ether, dimethyl ether,tetrahydrofuran, dioxane, propylene oxide), esters (e.g., methylacetate, ethyl acetate, propyl acetate, isopropyl acetate, benzylbenzoate, butyl acetate, and isoamyl acetate), ketones (e.g., acetone,methyl butyl ketone, methyl ethyl ketone (MEK), cyclohexanone,isophorone, and methyl isobutyl ketone), diols diol-derivatives (e.g.,2-methoxyethanol, 2-ethoxyethanol), acids (e.g., formic acid and aceticacid), and hydrocarbon solvents (e.g., alkanes, alkenes, and alkynesgenerally with 12 carbon units or less, benzene, methylbenzene, xylene,and terpenes such as limonene). Suitable liquid 322 may also be mixturesof multiple liquids, and may include any combination of liquid mixtures.A suitable liquid 322 may also be mixed with the inorganic solventwater. In some embodiments, any one of the liquids described above mayalso be mixed with water or other miscible liquids to generate liquid322 that has desired characteristics.

In some embodiments, liquid 322 may include an amount of ethanol and/orisopropanol. Ethanol and/or isopropanol are widely available andrelatively inexpensive. In some embodiments, the amount of ethanoland/or isopropanol in liquid 322 may range from about 10% to about 20%,from about 20% to about 30%, from about 30% to about 40%, from about 40%to about 50%, from about 50% to about 60%, from about 60% to about 70%,from about 70% to about 80%, from about 10% to about 30%, from about 10%to about 40%, from about 10% to about 50%, from about 10% to about 60%,from about 20% to about 40%, from about 20% to about 50%, from about 20%to about 60%, from about 20% to about 80%, from about 30% to about 50%,from about 30% to about 60%, from about 30% to about 70%, from about 30%to about 80%, from about 40% to about 60%, from about 40% to about 70%,from about 40% to about 80%, from about 50% to about 70%, from about 50%to about 80%, from about 60% to about 80%, or from about 10% to about80%, by weight or by volume.

In some embodiments, to use ethanol and/or isopropanol as an organicsolvent in liquid 322, object 100 needs to be made of a material that issoluble or partially soluble in ethanol and/or isopropanol. In suchembodiments, examples of the materials that can be used for makingobject 100 may include polyamide copolymers, cellulose based polymers(e.g., nitrocellulose, cellulose acetate propionate (CAP), celluloseacetate butyrate (CAB), methyl cellulose and ethyl cellulose), and vinylacetal polymers.

FIG. 3A illustrates an exemplary nebulizer 212. Nebulizer 212 mayinclude a reservoir 324 for holding liquid 322. Nebulizer 212 mayinclude a membrane 320 and an absorbent material 323 placed betweenmembrane 320 and reservoir 324. Liquid 322 may be transported fromreservoir 324 to membrane 320 via wicking, i.e., capillary action. Othersuitable methods may be used to transport liquid 322 from reservoir 324to membrane 320, which may include, but are not limited to, a capillarytube, a tube and a pump, a gravity feed from another reservoir, or anyother suitable method.

Membrane 320 may be vibrated to generate the micro droplets of mist 104from liquid 322 transported to the membrane. Membrane 320 may be aporous, vibrating membrane. The use of membrane 320 may increase theefficiency for generating mist 104, may reduce the energy consumption ofnebulizer 212, and/or may reduce the equipment and/or hardware needed togenerate mist 104.

A material suitable for membrane 320 may have several hundred to severalthousand of pores or holes with average diameters ranging from about 1μm to about 10 μm, from about 1 μm to about 8 μm, from about 1 μm toabout 6 μm, from about 1 μm to about 4 μm, from about 2 μm to about 6μm, from about 4 μm to about 8 μm, from about 4 μm to about 10 μm, orfrom about 6 μm to about 10 μm. In other embodiments, membrane 320 mayhave any number and/or surface density of holes or pores sufficient togenerate the desired size and/or density of the micro droplets of mist104.

FIG. 3B illustrates another exemplary nebulizer 212. Nebulizer 212 mayinclude an ultrasonic atomizer 336 completely or partially immersed inliquid 322. Ultrasonic atomizer 336 may have a shape of a disk.Ultrasonic atomizer 336 may include a piezoelectric element, and mayvibrate and generate ultrasonic waves when applied with electric power.This vibration may agitate liquid 322 and may generate micro droplets ofmist 104 from liquid 322. In some embodiments, ultrasonic atomizer 336may include any suitable device that generates ultrasonic waves, such ashigh frequency ultrasonic waves.

FIG. 3C illustrates another exemplary nebulizer 212. Nebulizer 212 mayinclude a nozzle 328 having channel and configured to eject a compressedgas 330. Nozzle 328 may mix liquid 322 with gas 330 and may spray microdroplets forming mist 104. In such embodiments, nebulizer 212 usescompressed gas 330 passing through liquid 322 to generate micro dropletsof mist 104 from liquid 322.

In some embodiments, as shown in FIGS. 3A-3C, nebulizer 212 may includea heating element 325 to heat liquid 322 in reservoir 324. Heatingelement 325 may be used to increase the rate for generating mist 104and/or to obtain desired properties of the micro droplets of mist 104generated from liquid 322. Heating element 325 may not heat liquid 322to a temperature above the boiling point of liquid 322 so that liquid322 is not substantially vaporized. In some embodiments, liquid 322 maybe heated to a temperature ranging, for example, from about 25° C. toabout 60° C., from about 25° C. to about 40° C., from about 25° C. toabout 50° C., from about 25° C. to about 70° C., from about 25° C. toabout 30° C., or from about 25° C. to about 90° C.

Heating element 325 may also be included in chamber 210 to heat the airinside chamber 210 to a predetermined environmental temperature. Thepredetermined environmental temperature may vary depending on thematerial of object 100 and/or liquid 322 used to generate the microdroplets of mist 104. In some embodiments, to reach a desired smoothnessand/or roughness of the surface of object 100, a higher environmentaltemperature may avow a faster polishing or smoothing process. Thetemperature of the air in chamber 210 may not exceed the lowesttemperature among a glass transition temperature of the material ofobject 100, a melting temperature of the material of object 100, and aboiling temperature of liquid 322. The predetermined environmentaltemperature may range, for example, from about 25° C. to about 60° C.,from about 25° C. to about 40° C. from about 25° C. to about 50° C.,from about 25° C. to about 70° C., from about 25° C. to about 80° C., orfrom about 25° C. to about 90° C. depending on the specific process, theamount of time, the material and/or shape of a particular object 100,and/or a desired degree of smoothness for the surface of the particularobject 100.

As described above, in some embodiments, vinyl acetal polymers may beused for making object 100. Vinyl acetal polymers are suitable formaking object 100 at least due to their good solubility in alcohols,such as ethanol and isopropanol, and their good printability foradditive manufacturing processes, such as FDM® or FFF. In someembodiments, exemplary vinyl acetal polymers used for making object 100may be represented by the chemical structure schematically shown in FIG.4 .

Vinyl acetal polymers are generally produced by a two-step chemicalprocess: (1) hydrolyzing poly (vinyl acetate) to form polyvinylalcohol), and (2) reacting poly(vinyl alcohol) with an aldehyde or mixedaldehydes to form predominantly 1,3-dioxane rings. The reactions aretypically incomplete. Therefore, as shown in FIG. 4 , acetal polymersare usually composed of a mixture of vinyl acetate units (“z”), vinylalcohol units (“y”), and vinyl acetal units (“x”). The R group shown inFIG. 4 may depend on the aldehyde and may be any hydrocarbon group. Insome embodiments, the R group may be selected, for example, from —H,—CH₃, —C₂H₅, —C₃H₇, and —C₄H₉. In one embodiment, the R group is —C₄H₉,and the resulting polymer is commonly referred to as poly(vinyl butyral)or PVB.

In some embodiments, object 100 may be made of PVB. PVB is composed of amixture of vinyl acetate monomeric units, vinyl alcohol monomeric units,and vinyl butyral monomeric units (R=—C₃H₇) on its polymer backbone. Thecomposition, i.e., weight fractions of the monomer components, may beadjusted to achieve desired properties. In some embodiments, thecomposition of PVB for making object 100 may include vinyl acetate(e.g., from 0 wt % to 5 wt %), vinyl alcohol (e.g., from 10 wt % to 30wt %), and vinyl butyral (e.g., from 65 wt % to 90 wt %). In someembodiments, the composition of PVB for making object 100 may includevinyl acetate (e.g., from 0 wt % to 4 wt %), vinyl alcohol (e.g., from15 wt % to 25 wt %), and vinyl butyral (e.g., from 71 wt % to 85 wt %).Example 1 described below illustrates an exemplary PVB material for 3Dprinting object 100.

Example 1 Preparation of an Exemplary PVB Material

Raw PVB resin (B05HX made by Chang Chun Group, in the form of a finepowder) was first hued in an oven at 60° C. for 4 hours. It was thendry-blended with 0.03% of an anti-oxidant (B215 from BASF) and 0.5% oftitanium dioxide (R-902 from DuPont), and pelletized using a 20 mmtwin-screw extruder.

The pellets were then dried at 60° C. for another 4 hours andgravity-fed to a 20 mm single-screw extruder to manufacture it into afilament. The temperatures used for manufacturing the PVB filament wereshown in Table 1.

TABLE 1 Exemplary processing temperatures Feed zone Compression zoneMetering zone Die 90° C. 160° C. 220° C. 190° C.

The extrudate, pulled by a puller at a constant speed, was cooled in awater tank, and collected on a spool. The puller speed was set to drawthe filament to a final diameter of about 1.75 mm. The spooled filamentwas then dried before printing object 100.

In some embodiments, the material for making object 100 disclosed hereinmay further comprise at least one additive, selected from, for example,colorants, pigments, dyes, fillers, fibers, plasticizers, nucleatingagents, pharmaceutical agents, heat and/or UV stabilizers, process aids,impact modifiers, chemicals, ceramics, biomaterials, other suitablepolymers, any suitable materials, or a combination thereof. Suitableadditives may be incorporated by a variety of methods, for example, meltcompounding. In some embodiments, the main polymer may still form thematrix or the continuous phase of the material after the addition of theat least one other ingredient.

Most FDM® or FFF printers for making object 100 may require thematerials to be in the form of a filament, usually with a circularcross-section. The filaments may be produced by a melt extrusionprocess. In the melt extrusion process, fully dried raw materials, alongwith other ingredients, are fed into a polymer extruder (eithersingle-screw or twin-screw) with a cylindrical die and are continuouslyextruded as an extrudate from a heated nozzle. The extrudate issubsequently quenched and/or cooled, and pulled by a puller to give thedesired physical dimensions before being collected. The melt extrusionprocess may also include other suitable equipment, such as melt or gearpumps (to ensure a stable output), laser micrometers (for on-linemeasurement of the physical dimensions), or other suitable devices.

The filaments may have an average diameter with small variations. Theaverage diameter of the filaments for making object 100 in an additivemanufacturing process may range, for example, from about 0.5 mm to about1 mm, from about 1 mm to about 1.75 mm, from about 1.75 mm to about 2.5mm, from about 1.75 mm to about 3 mm, or from about 3 mm to about 5 mm.The variation of the filament diameters may be advantageously reduced toa small value, and may range from about ±0.05 mm to about ±0.15 mm, forexample.

Various factors may affect the roughness of the surface of object 100made using an additive manufacturing process, including e.g., theaverage diameter of filaments and/or the thickness of a layer depositedby the additive manufacturing process using the filaments. In oneexample, a larger average diameter of the filaments and/or a greaterthickness of the layer may increase the difference between high and lowpoints on the surface of object 100, which may increase the roughness ofthe surface of object 100. In another example, a smaller averagediameter of the filaments and/or a smaller thickness of the layer mayreduce the difference between the high and low points on the surface ofobject 100, which may reduce the roughness of the surface of object 100.However, a smaller average diameter of the filaments and/or a smallerthickness of the layer may increase the number of passes needed tomanufacture object 100 by the additive manufacturing process, and thusmay increase the time for manufacturing object 100.

The roughness, e.g., degree of roughness of the surface of object 100may be measured before and after object 100 is subjected to the methodsand/or processing disclosed in the present disclosure. Profilometry orother suitable methods may be used to measure the degree of roughness ofthe surface of object 100. Example 2 described below illustrate themeasurement and comparison of the roughness of the surface of exemplaryobjects 100 before and after being processed.

Example 2 Measurement of the Roughness of the Surface of ExemplaryObjects 100

A compounded material was prepared for making exemplary objects 100 by(1) manually mixing all of the ingredients as shown in Table 2 in theformulation (2) melt compounding the ingredients using a 20 mmco-rotating twin-screw extruder under the conditions listed in Table 3,and (3) manufacturing the compounded material into a filament with anaverage diameter of 1.75 mm via single-screw extrusion, under theextrusion conditions listed in Table 4.

TABLE 2 The formulation of a compounded material for making an exemplaryobject 100 Content (phr*) PVB (B05HX from Chang Chun Group) 100Anti-Oxidant (B215 from BASF) 0.3 Nitrile Rubber 15 (P35 from OMNOVASolutions) *“phr” means parts per hundreds of resin.

TABLE 3 Melt compounding conditions Feed 2^(nd) 3^(rd) 4^(th) Zone ZoneZone Zone Die RPM Temperature (° C.) 120 160 190 200 190 120

TABLE 4 Filament extrusion conditions Feed Compression Metering ZoneZone Zone Die RPM Temperature (° C.) 90 170 200 190 30

The resulted filament was used to print exemplary objects 100, i.e., 15mm by 15 mm by 30 mm cuboids, as test specimens (0.2 mm layer height;shell number=2; 20% infill; printing temperature=210° C.). The testspecimens were polished using an exemplary apparatus 200 that includesan exemplary vibrating mesh nebulizer 212 with an overall diameter ofabout 20 mm, a vibrating frequency of about 112 kHz, and about 850 holeswith an average diameter of about 8 μm. Apparatus 200 had an internalvolume of about 3 L. The polishing time was 20 min.

As-printed and polished specimens were tested for surface roughnessusing a roughness tester (Mitutoyo Surftech SJ400). Scanning of thesurface of the specimens was performed in a direction parallel to the“z” direction (perpendicular to the layers). The results are shown belowin Table 5.

TABLE 5 Comparison of surface roughness of processed and unprocessedspecimens R_(a) (μm) R_(z) (μm) As-printed 15.65 95.9 Polished (20 min)2.61 9.1

In Table 4, R_(a) and R_(z) are commonly used parameters indicatingsurface roughness. As described herein, R_(a) refers to the arithmeticaverage of the absolute values of the distances between the peaks—bothpositive peaks and negative peaks (valleys)—and the medium line, andR_(z) refers to the arithmetic mean value of the single roughness depthsof consecutive sampling lengths. As shown in Table 4, the specimenspolished or processed by apparatus 200 showed substantially improvedsurface smoothness and/or reduced surface roughness compared to theas-printed specimens.

Example 3 described below illustrate processing an exemplary object 100using exemplary apparatus 200 in accordance with the present disclosure.

Example 3 Processing 3D-Printed Object 100 Using an Exemplary Apparatus200

An exemplary apparatus 200 substantially similar to that shown in FIG. 2was used. Apparatus 200 included an exemplary rotatable platform 213 forplacing an exemplary 3D-printed 100, a nebulizing unit with twoexemplary vibrating membrane nebulizers 212, and electrical circuitsconfigured to power the nebulizing unit as well as the structuralcomponents.

An owl model (about 12 cm tall) was printed on a FlashForge Creator Prodesktop 3D printer using the filament prepared as described in Example1, under the following printer settings: printing/nozzle temperature:210° C.; build plate temperature: 60° C.; printing speed: 60 mm/s; layerheight: 0.2 mm.

The printed owl model was processed or polished in apparatus 200 forabout 40 min using isopropanol as an exemplary liquid 322. Afterprocessing or polishing, the owl model was removed from apparatus 200and the surface of the owl model dried off under natural evaporation ofisopropanol for several hours. The processed or polished 3D-printedobject 100, the owl model, exhibited a much smoother and shiny surfacecompared to that before the processing by apparatus 200.

FIGS. 5A-C illustrate another exemplary apparatus 200 in accordance withthe present disclosure. As shown in FIG. 5A, chamber 210 of apparatus200 may have transparent or semi-transparent walls such that object 100may be viewed by a user of apparatus 200. For example, the transparentor semi-transparent chamber 210 may allow the user to place object 100on rotatable platform 213 or a fixture plate 214 at a suitable place,for example, the middle or adjacent nebulizer 212. The transparent orsemi-transparent chamber 210 may allow the user to observe the progressof the processing of object 100, the generation, density, and/ordistribution of mist 104 in chamber 210, the smoothness of the surfaceof object 100, the rotation of object 100 during processing, and/or anydesirable or undesirable effect or situation during the processing ofobject 100.

In some embodiments, as shown in FIG. 5A, apparatus 200 may include usercontrol 211. In some embodiments, user control 211 may be a rotarycontrol knob such that that the operation of apparatus 200 may beswitched among different settings by turning the knob. Each setting maycorrespond to an operation of apparatus 200, such as starting orterminating nebulizer 212. In some embodiments, as shown in FIG. 5B,user control 211 may include one or more buttons, each corresponding toa function or setting of one or more of the components of apparatus 200.In some embodiments, user control 211 may include one or more displaysthat indicate parameters for the processing of object 100, including,e.g., the duration of the processing, the environmental temperature,and/or humidity in chamber 210. In some embodiments, user control 211may be a display having a graphical user interface and one or moresettings for the operation of apparatus 200 may be selected from theinterface. In other embodiments, user control 211 may be any suitabletype of user interface for controlling and/or adjusting the operation ofapparatus 200.

FIG. 5C illustrates a cross-section of the exemplary apparatus 200 shownin FIG. 5A. As shown in FIG. 5C, in some embodiments, apparatus 200 mayinclude one or more control circuits 217. Control circuits 217 may beelectrically connected to user control 211, nebulizer 212, and/or othercomponents of apparatus 200 to be described further below. In someembodiments, control circuits 217 may receive one or more electricalsignals according to an adjustment or setting of user control 211, e.g.,turning a rotary control knob to a setting position or pressing abutton. Control circuits 217 may send electrical signals, such as acurrent, a current pulse, a voltage level, a voltage pulse, or atransient voltage level to a suitable component of apparatus 200, suchas nebulizer 212. Upon receiving an electrical signal from controlcircuits 217, for example, nebulizer 212 may start generating mist 104or stop generating mist 104.

In some embodiments, fixture plate 214 may be removably or fixedlyplaced on top of rotatable platform 213 such that fixture plate 214 mayrotate in the same motion as rotatable platform 213 and/or rotationalmotor 220. Fixture plate 214 may be a separate part from rotatableplatform 213 or an integrated part with rotatable platform 213. Object100 may be removably placed and/or temporarily fixed on fixture plate214 during the processing such that object 100 may rotate in the samemotion as fixture plate 214 and rotatable platform 213.

In some embodiments, as shown in FIGS. 5A-5C, chamber 210 may include alid 218. Lid 218 may include one or more seals along its perimeter tocreate a sealing of chamber 210 when lid 218 is closed. Lid 218 may beopened or closed manually or automatically. For example, lid 218 may beopened to receive object 100 into chamber 210 or to allow object 100 tobe taken out of chamber 210. In some embodiments, lid 218 may include amotor that is electrically connected to control circuits 217. In someembodiments, lid 218 may be closed before nebulizer 212 start generatingmist 104. In some embodiments, lid 218 may be opened after nebulizer 212stops generating mist 104 and/or after mist 104 substantially is reducedor disappears. In some embodiments, lid 218 may be automatically closedbefore the processing of object 100 starts and/or may be automaticallyopened after the processing of object 100 ends. The operation of lid 218may be coordinated with the processing of object 100 and/or theoperation of other components of apparatus 200, for example, nebulizer212.

In some embodiments, as shown in FIG. 5C, apparatus 200 may include aplate 224 between chamber 210 and chamber 216. Rotatable platform 213may be placed on top of plate 224 or may be installed in an opening ofplate 224. In some embodiments, nebulizer 212 may be installed on plate224 and plate 224 may be located between chamber 210 and reservoir 324.In some embodiments, some regions of plate 224 may have porous membrane215 or a plurality of openings, which may allow the micro droplets ofmist 104 in chamber 210 to pass, such as flow, diffuse, and/or disperse,through into chamber 216 and/or reservoir 324.

As described above and shown in FIG. 5C, apparatus 200 may includerotational motor 220. Rotational motor 220 may be removably or fixedlycoupled to rotatable platform 213. Rotational motor 220 may beelectrically connected to control circuits 217 and may be configured toreceive electrical signals from control circuits 217. The operation ofrotational motor 220, e.g., duration and speed of rotational motor 220,may be adjusted or controlled by user control 211, and may becoordinated with the operation of nebulizer 212. In one example,rotational motor 220 may start to operate when the processing of object100 starts or nebulizer 212 starts. In another example, rotational motor220 may stop to operate when the processing of object 100 ends ornebulizer 212 stops. In some embodiments, the rotational speed ofrotational motor 220, and thus that of rotatable platform 213 and/orfixture plate 214, may be adjusted or controlled by user control 211before or during the processing of object 100.

In some embodiments, user control 211 may be adjusted based on anobservation of object 100 and/or the environment in chamber 210, such asthe density and/or distribution of mist 104. For example, user control211 may be adjusted to regulate and/or to control the processing ofobject 100, such as to stop nebulizer 212 from generating mist 104 whenthe smoothness of object 100 observed is satisfactory or to startnebulizer 212 to generate mist 104 when the smoothness of object 100observed is not satisfactory. In some embodiments, based on theobservation of the surface of object 100, user control 211 may beadjusted to start rotational motor 220 and/or to increase the rotationalspeed of rotational motor 220 to improve the evenness of thedistribution of mist 104 surrounding object 100 and/or the evenness ofthe smoothness of the surface of object 100. In other embodiments, usercontrol 211 may be adjusted to stop rotational motor 220 and/or toreduce the rotational speed of rotational motor 220.

In some embodiments, nebulizer 212 may have different operation modes togenerate mist 104. For example, nebulizer 212 may generate a continuousflow of mist 104, or a discontinuous flow of mist 104, such as anintermittent, a pulsatile, or randomly generated bursts of mist 104. Inone aspect, nebulizer 212 may generate a series of intermittent orpulsatile bursts of mist 104 for a predetermined amount of time. Inanother aspect, nebulizer 212 may generate a continuous flow of mist 104for a first amount of time and intermittent bursts of mist 104 for asecond amount of time. The bursts of mist 104 may be before and/or afterthe continuous flow of mist 104. In some embodiments, nebulizer 212 mayoperate at an operation mode or a sequence of operation modespreprogramed in control circuits 217. For example, control circuits 217may include a memory device that stores one or more predeterminedinstructions for the operation of nebulizer 212. Control circuits 217may include one or more processing circuits configured to execute theinstructions to allow nebulizer 212 to perform one or more operationmodes for a period of time, e.g., by adjusting electrical signals sentto nebulizer 212 or a driver circuit of nebulizer 212. In someembodiments, control circuits 217 may include a timer circuit thatrecords the total duration for the operation of nebulizer 212, aduration for a continuous operation of nebulizer 212, and/or a timeinterval between intermittent operations of nebulizer 212.

In some embodiments, nebulizer 212 may operate at an operation mode or asequence of operation modes in response to a setting received from usercontrol 211. In some embodiments, according to the setting of usercontrol 211, nebulizer 212 may generate mist 104 in a selected operationmode or a selected Sequence of operation modes stored in the memorydevice of control circuits 217. In some embodiments, nebulizer 212 mayoperate at different modes or a sequence of operation modes to generatemist 104 to obtain a satisfactory distribution of the micro droplets ofmist 104 and/or a satisfactory evenness of the smoothness of the surfaceof object 100.

Increasing the uniformity of the distribution of the micro droplets ofmist 104 in chamber 210 and/or the distribution of the micro droplets ofmist 104 surrounding object 100 may increase the evenness and/oruniformity of the smoothing of the surface of object 100 (e.g., evennessand/or uniformity of smoothness or a degree of smoothing of the surfaceof object 100). The intermittent or pulsatile bursts of mist 104 maycreate and/or increase turbulence in the air in chamber 210, which mayincrease the uniformity of the distribution of the micro droplets ofmist 104 in chamber 210 and may thus increase the uniformity or evennessof the smoothing of the surface of object 100 after the processing byapparatus 200.

In some embodiments, as shown in FIGS. 5A, 5C, 6A, and 6B, apparatus 200may include a lifting mechanism that may move object 100 into and out ofchamber 210. The lifting mechanism of apparatus 200 may include at leastone of a lifting arm 228. Lifting motor 230 may be electricallyconnected to control circuits 217. In some embodiments, lifting motor230 and/or lifting arm 228 may operate according to an input receivedfrom user control 211, e.g., a setting to start or terminate nebulizer212. In other embodiments, lifting motor 230 and/or lifting arm 228 mayoperate in coordination with other components of apparatus 200. Forexample, lifting motor 230 and lifting arm 228 may start performinglinear motion when nebulizer 212 starts or stops to operate, or when theprocessing of object 100 starts or ends. The linear motion of liftingarm 228 may include moving upwards to raise object 100, e.g., from aninitial rest position inside chamber 210 to a second rest position whereobject 100 is presented out of chamber 210, and may include movingdownwards to lower object 100, e.g., from the second rest positiontowards the initial rest position. During the movement of lifting arm228, lifting motor 230 may stay at a base location of apparatus 200.

In some embodiments, lifting motor 230 may be a manually operated linearactuator that combines a rotational arm and a mechanical actuator thatconverts the rotary motion of the rotational arm into linear motion oflifting arm 228. For example, a user may manually rotate the rotationalarm and then the mechanical actuator converts the rotary motion of therotational arm to linear motion of lifting arm 228 to raise or lowerobject 100.

In some embodiments, as shown in FIGS. 5C, 6A, and 6B, lifting arm 228may be connected to lid 218. Lid 218 may move in the same linear motionas lifting arm 228. As shown in FIG. 5C, when lifting arm 228 is at afirst rest position, lid 218 is closed and may form a seal with a topcover 219 of chamber 210. As shown in FIGS. 6A and 6B, when lifting arm228 is at a second rest position, lid 218 is moved away from top cover219.

In some embodiments, as shown in FIGS. 5C, 6A, and 6B, lifting arm 228may be connected to lifting plate 228. Lifting plate 226 may move in thesame linear motion as lifting arm 228. Lifting plate 228 may be, forexample, donut-shaped or ring-shaped and may have an inner perimeter andan outer perimeter. The inner perimeter of lifting plate 226 may besmaller than the outer perimeter of fixture plate 214 and larger thanthe outer perimeter of rotatable platform 213. As shown in FIG. 5C, whenlifting arm 228 is at the initial rest position, lifting plate 226 maysurround the rotatable platform 213 and/or may be at least partiallylocated beneath an edge area of fixture plate 214. Lifting plate 226 mayengage with fixture plate 214 and/or rotatable platform 213 to raise orlower object 100 in a linear vertical motion.

In some embodiments, object 100 placed on fixture plate 214 may moveupwards or downwards in the same motion as lifting plate 226 and liftingarm 228. For example, when lifting plate 226 moves upwards with liftingarm 228, fixture plate 214 may engage at least partially with a topsurface of lifting plate 226 and/or may temporarily be releasablyconnected to lifting plate 226 such that fixture plate 214 may besupported by lifting plate 226. In such instances, as lifting plate 226moves upwards, fixture plate 214 may move upwards together with liftingplate 226 and away from rotatable platform 213. The upward movement oflifting plate 226 and lifting arm 228 may be stopped at the second restposition where lifting plate 226 meets or abuts top cover 219 of chamber210. As lifting plate 226 moves downwards with lifting arm 228, fixtureplate 214 may move downwards toward rotatable platform 213 until liftingarm 228 moves back to the first rest position. At this initial restposition, lifting plate 226 may disengage with and be moved away fromfixture plate 214, which may be then removably placed on and/orconnected to rotatable platform 213.

Lifting arm 228, lifting motor 230, lifting plate 226, and/or lid 218may be controlled by control circuits 217 and may be coordinated withthe processing of object 100. For example, before processing of object100, fixture plate 214 may be lifted away from rotatable platform 213and lid 218 may be moved away from top cover 219 to a position preparedto receive object 100. Object 100 may be then received on fixture plate214, which may be lowered back to rotatable platforms 213 and lid 218may be closed. Nebulizer 212 then may start generating mist 104 andprocessing of object 100 may start. After processing of object 100,fixture plate 214 may be again lifted away from rotatable platform 213and lid 218 may again be moved away from top cover 219, presentingprocessed object 100 out of chamber 210 for inspection and/or retrieval.In some embodiments, apparatus 200 may automatically perform theoperation of the lifting mechanism by performing a sequence ofinstructions saved in the memory device of control circuits 217. Inother embodiments, the operation of the lifting mechanism may beperformed manually at the suitable time point.

The lifting mechanism may advantageously reduce the need to removechamber 210, keep chamber 210 remain substantially sealed, reduce orlimit the evaporation of liquid 322 from chamber 216 or reservoir 324,and/or may reduce or limit the release of mist 104 out of chamber 210.In some embodiments, even when lid 218 is open, during the placement andretrieval of object 100 after the processing of object 100. This liftingmechanism may offer a convenient way to place object 100 inside ofchamber 210, e.g., onto fixture plate 214 or rotatable platform 213, andto retrieve object 100 out of chamber 210, e.g., from fixture plate 214or rotatable platform 213. In some embodiments, the linear movement ofobject 100 by the lifting mechanism may increase the removal of residueliquid 322 on the surface of object 100 after the processing by allowingthe residue liquid 322 to drip away and/or evaporate during themovement.

FIG. 7A illustrates another exemplary nebulizer 212 for generating mist104 in apparatus 200. In some embodiments, as shown in FIG. 7A,nebulizer 212 may include a cartridge 700 holding a nebulizer assembly730. Cartridge 700 may include a top part 710 and a bottom part 720. Insome embodiments, top part 710 and bottom part 720 may be releasablyfitted together via, e.g., friction fit, press fit, twist fit, snap fit,overmolding or molding, thermal bonding, and/or welding. In someembodiments, top part 710 and bottom part 720 may be fixedly fittedtogether, for example, via an adhesive or a screw mechanism. Forexample, top part 710 and bottom part 720 may comprise a set ofcomplementary screw threads such that top part 710 may be fastened tobottom part 720 by screwing one or more screws into bottom part 720. Insome embodiments, top part 710 and bottom part 720 may have one or moreexternal recesses, e.g., recesses 716 and 728, to increase theconvenience for a user to grab, carry, or assemble cartridge 700 and/ornebulizer assembly 730.

The structure of top part 710 and bottom part 720 may be designed andconfigured to hold nebulizer assembly 730 at least in part, in cartridge700, and to allow mist 104 to exit from nebulizer assembly 730.Cartridge 700 may include a fitting part 740 that engages with bottompart 720, for example, to stabilize and/or fix nebulizer assembly 730 incartridge 700.

In some embodiments, top part 710 may include a rim 712 and an opening714. Rim 712 may have a truncated funnel shape. In some embodiments,opening 714 may have a geometric shape, such as a circle or an ellipse.In other embodiments, opening 714 may have a tubular shape, such as acylinder having a cylindrical wall. For example, opening 714 may becircular or elliptical, and may be surrounded by a cylindrical wall. Rim712 may be formed above opening 714 and/or above the wall of opening714. In some embodiments, the inner perimeter of the bottom of rim 712may be smaller than the inner perimeter of opening 714. In otherembodiments, opening 714 and rim 712 may be any suitable geometric shapeand/or size.

In some embodiments, bottom part 720 may include one or more fittingportions to fit top part 710 and nebulizer assembly 730. In someembodiments, bottom part 720 may include a first chamber 722, a secondchamber 724, and a fitting edge 726. First chamber 722 may have ageometric shape sized substantially complementary to that of opening 714of top part 710. For example, the inner perimeter of first chamber 722may be about the same as the outer perimeter of opening 714. In suchsituations, top part 710 may engage with bottom part 720 via, e.g.,friction fit, press fit, twist fit, snap fit, overmolding or moldingthermal bonding, and/or welding between the inner surface of firstchamber 722 and the outer surface of a wall of opening 714.

In some embodiments, nebulizer assembly 730 includes one or morecomponents, such as a piezoelectric vibrating element 731, a mesh 732, acoupler 734, and a wick 736. The perimeter of vibrating element 731 maybe the same as that of the inner perimeter of first chamber 722.Vibrating element 731 may have an edge portion 733 that may rest upon abottom edge 723 of first chamber 722. In some embodiments top part 710may be pushed and/or twisted against bottom part 720 until the wall ofopening 714 abuts edge portion 733 of vibrating element 731 or bottomedge 723 of first chamber 722. Vibrating element 731 may have a ringshape with a hole in the middle and mesh 732 may be installed in thehole or may cover the hole. In some embodiments, mesh 732 and vibratingelement 731 are one integrated part. In some embodiments, coupler 734may be placed in second chamber 724 of bottom part 720, and may have atop surface 735 and a bottom surface 737. Coupler 734 may be in contactwith vibrating element 731 and/or mesh 732 on top surface 735 and may bein contact with wick 736 on bottom surface 737. Mesh 732, coupler 734,and wick 736 are configured to be in fluid communication. During theoperation of nebulizer assembly 730, a distal end 738 of wick 736 issubmerged in liquid 322 such that liquid 322 is transported and suppliedto coupler 734 and/or mesh 732 in a substantially continuous fashion.

In some embodiments, fitting part 740 allows coupler 734 and wick 736 tobe held in place in cartridge 700. In one example, fitting part 740 mayinclude an inner tube 743 that has a perimeter substantially the same asor smaller than that of the outer perimeter of wick 736. Fitting part740 may engage with wick 736 via any suitable means, e.g., friction fit,twist fit, thermal bonding, and/or welding. Fitting part 740 may abutbottom surface 737 of coupler 734, and may engage with bottom part 720via any suitable means, e.g., friction fit, press fit, twist fit, snapfit, overmolding or molding, thermal bonding, and/or welding. Forexample, fitting part 740 may include one or more springy cantileversand may be pushed and/or twisted through wick 736 and/or against fittingedge 726 until the cantilevers pass and rest on fitting edge 726. Inother embodiments, nebulizer 212 may include any suitable means to fixnebulizer assembly 730 in cartridge 700.

Vibrating element 731 may vibrate, e.g., contract or expand, bendingupwards or downwards, upon being applied of an electric current orvoltage. Mesh 732 may vibrate along with vibrating element 731. Duringvibration, mesh 732 may generate micro droplets of mist 104 from liquid322 transported to mesh 732 by coupler 734 and/or wick 732. Mesh 732 maybe made of a porous material that has several hundred to severalthousand of pores or holes with average diameters ranging from about 1μm to about 10 μm, from about 1 μm to about 8 μm, from about 1 μm toabout 6 μm, from about 1 μm to about 4 μm, from about 2 μm to about 6μm, from about 4 μm to about 8 μm, from about 4 μm to about 10 μm, orfrom about 6 μm to about 10 μm. In other embodiments, mesh 732 may haveany suitable number and/or surface density of holes or pores sufficientto generate the desired size and/or density of micro droplets of mist104.

In some embodiments, wick 736 may be made of a material that absorbsliquid 322 from chamber 216 or reservoir, and draws up absorbed liquid322 to mesh 732 and/or coupler 734 via capillary action. In someembodiments, wick 736 may be made of a material that has pores and/orchannels, such as a sponge material or a foamed plastic polymer, e.g.,polyester, PVA, cotton fibers, or cellulose fibers. In otherembodiments, wick 732 may be made of a non-porous material, e.g., carbonfibers. In other embodiments, wick 732 may be a thin tube. The materialof wick 732 may not substantially affect or react with liquid 322.

Nebulizer assembly 730 may operate with or without coupler 734. Whencoupler 734 is not used, an amount of space between mesh 732 and wick736 may affect the vibration of mesh 732 and/or vibrating element 731.For example, when the space between mesh 732 and wick 736 is reduced,vibrating element 731 and/or mesh 732 may contact wick 736 as itvibrates, e.g., bending upwards and downwards. Such contact may apply ormay increase a pressure on mesh 732 and/or vibrating element 731, whichmay affect the normal vibration of mesh 732 and/or vibrating element 731and may eventually affect normal generation of mist 104, e.g.,disrupting or reducing the generation of mist 104. When the spacebetween mesh 732 and wick 736 is increased, wick 736 may not contact andmay be away from vibrating element 731 and/or mesh 732 such thattransportation and/or supply of liquid 322 to mesh 732 may be affected,which may also affect the generation of mist 104. Thus, the amount ofspace between mesh 732 and wick 736 needs to be suitably designed andplaced. For example, a suitable amount of space tailored to allow wick736 to minimally contact vibrating element 731 and/or mesh 732. However,such configuration for the placement of wick 736 and vibrating element731 and/or mesh 732 may increase the complexities for assemblingnebulizer assembly 730 and/or may reduce the consistency of nebulizerassembly 730 in generating mist 104.

To reduce the complexities in designing nebulizer assembly 730 and/or toimprove the consistency of the operation of nebulizer assembly 730,coupler 734 may be advantageously added between vibrating element 731and wick 736. Coupler 734 may be made of a soft material that may deformwhen applied with a pressure and may resume its form when the pressureis removed. Coupler 734 may absorb the pressure applied by vibratingelement 731, mesh 732, and/or wick 736. Coupler 734 may also increase adistribution of pressure absorbed from vibrating element 731, mesh 732,and/or wick 736. Thus, coupler 734 may reduce the impact of wick 736 onvibrating element 731 and/or mesh 732 by resiliently deforming andreforming during the movement of vibrating element 731 and/or mesh 732.In one example, when the vibrating element 731 and/or mesh 732 bendsdownward and applies a pressure to top surface 735, coupler 734 deforms,and when the vibrating element 731 and/or mesh 732 bends upward andrelieves the pressure on top surface 735, coupler 734 reforms. Due tothe resilient nature of the material of coupler 734, the changes of theforms of coupler 734 may not substantially affect the contact and/or thepressure between top surface 735 and vibrating element 731 and/or mesh732, and/or may not substantially affect the contact and/or the pressurebetween bottom surface 737 and wick 732. In such instances,transportation and/or supply of liquid 322 from wick 732 to mesh 732 maynot be substantially affected and the operation of nebulizer assembly730 may not be substantially affected. Thus, coupler 734 may facilitatethe transport of liquid 322 to mesh 732, and may improve the operationnebulizer assembly 730 for generating mist 104.

The material of coupler 734 may be described as a foamy material, asquishy material, a resilient material, and/or a resiliently deformablematerial. Any suitable material that has the properties discussed aboveand also conducts liquids via capillary action may be used for coupler734. For example, coupler 734 may be made of any suitable materialselected from materials with foam-like textures, soft sponge materials,e.g., melamine sponge, resilient cloth wadding, or cotton pad. Thematerial of coupler 734 may not substantially affect, dissolve in,and/or react with liquid 322. In some embodiments, coupler 734 may bemade with the same material as that of wick 736 described above. Inother embodiments, wick 736 may be made with the same material as thatof coupler 734 described above.

As shown in FIG. 7B, in some embodiments, coupler 734 and wick 736 maybe one integrated part. The material of the integrated part may be madeof the material of coupler 734 described above. The integrated part maybe fit into bottom part overmolding or molding, thermal bonding, and/orwelding. In such instances, as shown in FIG. 7B, fitting edge 726 andfitting part 740 may not be needed to engage integrated wick 736 andcoupler 734 with bottom part 720. Wick 736 and coupler 734 may have anysuitable shape, e.g., cylindrical, rectangle, polygonal, etc. Thesoftness, compliance, or deformability of the material of coupler 734allows any shape of coupler 734 fit in chamber 724 of bottom part 720,via, e.g., friction fit, squeeze fit, press fit, twist fit, snap fit,overmolding molding, thermal bonding, and/or welding. The body of wick736 or the integrated part of wick 736 and coupler 734 may be consistentin size along the length of its length or may vary, e.g., taper and/orflare. The integration of the wick 736 and coupler 734 simplifies thedesign of the nebulizer assembly 730, and reduces the impact of thepressure between wick 736 and coupler 734 on the generation of mist 104by nebulizer assembly 730.

Nebulizer assembly 730 may further include a driver circuit 750 fittedin a chamber formed by top part 710 and bottom part 720. In someembodiments, vibrating element 731 may have two electrical connectionswith driver circuit 750. Vibrating element 731 may vibrate, e.g.,contract or expand, according to electrical signals, e.g., electriccurrent or voltage, it receives from driver circuit 750. In someembodiments, driver circuit 750 may be electrically connected to controlcircuits 217 such that the operation of vibrating element 731 may becontrolled or adjusted by control circuits 217 and/or user control 211.In one example, electric current generated by driver circuit 750 to besupplied to vibrating element 731 may be adjusted Or controlled bycontrol circuits 217. In another example, when user control 211 receivesan input, e.g., a setting to start processing object 100, controlcircuits 217 may determine an operation mode of nebulizer 212, and maysend one or more continuous, pulsatile, or intermittent electricalsignals, e.g., current and voltage, to driver circuit 750, which arethen supplied to vibrating element 731. Vibrating element 731 mayvibrate in a continuous, an intermittent, or in a pulsatile modecorresponding to the electrical signals it receives. In someembodiments, the magnitude of vibration of vibrating element 731 maydepend on the magnitude of the electrical signal it receives from drivercircuit 750, which may be adjusted or controlled by control circuits217. For example, when user control 211 receives an input, e.g., asetting to start processing object 100, control circuits 217 maydetermine a magnitude of the electrical signal sent to driver circuit750 which may send a corresponding electrical signal to vibratingelement 731.

In some embodiments, vibrating element 731 may vibrate at apredetermined frequency according to stored parameters in the memorydevice in control circuits 217 and/or an input from user control 211. Insome embodiments, the frequency at which vibrating element 731 operatesrosy depend on the piezoelectric material of vibrating element 731. Insome embodiments, vibrating element 731 may vibrate at a frequencyranging from about 100 kHz to about 200 kHz. In some embodiments, theamount, size, and/or density of the micro droplets of mist 104 may varydepending on the frequency at which vibrating element 731 operates.

In some embodiments, nebulizer assembly 730 may be disposed after anumber of uses and may be replaced with a new set of nebulizer assembly730. In outer embodiments, nebulizer assembly 730 may be disposedtogether with cartridge 700 after a number of uses, and both may bereplaced. In other embodiments, one or more of the components ofnebulizer assembly 730, such as vibrating element 731, coupler 734, mesh732, and/or wick 736, may be disposed after a number of uses and may bereplaced.

In some embodiments, as shown in FIG. 8 , cartridge 700 may be placed ina fixture 232 on plate 224. The shape of fixture 232 may besubstantially complementary to that of top part 710 and/or bottom part720. Fixture 232 may be releasably or fixedly fitted together with toppart 710 and/or bottom part 720 via, e.g., friction fit, press fit,twist fit, snap fit, overmolding or molding, thermal bending, welding,and/or via an adhesive or a screw mechanism. For example, bottom part720 may be pushed, twisted against, and/or may abut a bottom edge offixture 232, and may, additionally or alternatively, be fastened tofixture 232 by screwing one or more screws through bottom part 720 intofixture 232.

In some embodiments, plate 224 may have a concave surface curved towardschamber 216 and/or reservoir 324. In some embodiments, as shown in FIG.8 , plate 224 may include one or more openings 234 distributed on thesurface of curved plate 224. For example, openings 234 may bedistributed at a lower location on the surface of plate 224 such thatmicro droplets of mist 104 that are condensed in chamber 210 mayaccumulate on plate 224 at the lower location and then be recollected tochamber 216 or reservoir 324 through openings 234. Such design of plate224, e.g., having curved surface and openings 234, may increase theefficiency of using liquid 322 and may reduce the amount of liquid 322used for processing object 100.

In some embodiments, fixture 232 may include one or more LEDs 240 thatmay illuminate mist 104 and/or object 100. LED 240 may be a single colorLED or a multi-color LED. LED 240 may be electrically connected tocontrol circuits 217 and/or the driver circuit 750, which may adjust orcontrol the operation of LED 240. For example, the selection of thecolor of illumination by LED 240 may be stored in the memory device ofcontrol circuits 217. In some embodiments, LED 240 may be adjusted orcontrolled according to an input received by user control 211. Forexample, when user control 211 receives an input, e.g., a setting tostart processing object 100, control circuits 217 or driver circuit 750may send a voltage and/or a current to LED 240 such that LED 240 mayilluminate in a predetermined color for an amount of time, e.g., aduration for the processing of object 100. In some embodiments, LED 240may be automatically turned on when nebulizer assembly 730 starts togenerate mist 104. In some embodiments, LED 240 may be automaticallyturned off when nebulizer assembly 730 stops generating mist 104.

In some embodiments, the color of LED 240 may change during theprocessing of object 100 and/or the operation of nebulizer assembly 730.For example, the color of LED 240 may change from a first color to asecond color when nebulizer assembly 730 has operated for an amount oftime longer than a predetermined threshold. In another example, thecolor of LED 240 may change before the end of the processing of object100 and/or the end of the operation of nebulizer assembly 730 toindicate the stage of the process, e.g., an ending of the process. Insome embodiments, the color of LED 240 may depend on object 100 and/orliquid 322, e.g., color or material of object 100 and/or mist 104.

In some embodiments, the illumination by LED 240 may be continuous,intermittent, or pulsatile in accordance with the operation mode ofnebulizer assembly 730. For example, control circuits 217 may apply apulsatile voltage or current to LED 240 such that a pulsatile mist 104generated by nebulizer assembly 730 may be accompanied by a pulsatileillumination by LED 240. The illumination of mist 104 by LED 240provides an aesthetic and/or interesting display of mist 104 and/orobject 100 in chamber 210.

As discussed above, increasing the uniformity of the distribution of themicro droplets of mist 104 in chamber 210 and/or the distribution of themicro droplets of mist 104 surrounding object 100 may increase theevenness and/or uniformity of the smoothing of the surface of object100, e.g., a substantially uniform degree of smoothness of the surfaceof object 100 after the processing. It is contemplated that one factorthat may decrease the uniformity of the distribution of the microdroplets of mist 104 in chamber 210 is a temperature gradient created bymist 104. During the generation of mist 104, micro droplets of mist 104may evaporate, which is an endothermic process that absorbs heat frommist 104. Thus, mist 104 cooled by the evaporation may stay aroundand/or move towards a lower part of chamber 210, leaving warmer air inan upper part of chamber 210, which may result in inadequate or reducedsmoothing of the surface of a top part of object 100. In a chamber 210of a smaller size, this effect of the temperature gradient on thedistribution of the micro droplets of mist 104 in chamber 210 may bereduced by the intermittent or pulsatile bursts of mist 104 generated bynebulizer 212, but in a chamber 210 of a larger size, this effect maynot be effectively reduced by the intermittent or pulsatile bursts ofmist 104.

For the above reasons, in some embodiments, apparatus 200 may include anair-agitating device to increase the uniformity of the distribution ofthe micro droplets of mist 104 in chamber 210 and/or surrounding object100. The air-agitating device may create and/or increase thedistribution of the micro droplets of mist 104 in chamber 210, e.g., themicro droplets surrounding object 100, by creating and/or increasing themovement and/or turbulence of the air in chamber 210, which may reduceor substantially reduce the temperature gradient chamber 210. In someembodiments, creating and/or increasing the movement and/or turbulenceof the air in chamber 210 may further increase the movement of the microdroplets of mist 104. Reducing or eliminating the temperature gradientin chamber 210 and/or increasing the movement of the micro droplets ofmist 104 may substantially increase the uniformity of the distributionof the micro droplets of mist 104 in chamber 210, and may, for example,allow a substantial uniform distribution of the micro droplets of mist104 surrounding object 100. In such instances, the evenness or theuniformity of the smoothing of the surface of object 100 may beincreased. For example, the surface of a top part of object 100 and thesurface of a bottom part of object 100 may be surrounded or exposed tosubstantially similar distributions of the micro droplets of mist 104,and thus may have a substantial similar surface roughness or smoothnessafter the processing of object 100.

In some embodiments, the air-agitating device may be a fan 930. Fan 930may be installed at a place in chamber 210 that may suitably reduce thetemperature gradient in chamber 210 and/or increase the movement of themicro droplets of mist 104. In some embodiments, fan 930 may beinstalled, for example, in lid 218. As shown in FIGS. 9A-9C, lid 218 mayinclude an upper housing 900 and a lower housing 910. Upper housing 900and lower housing 910 may be releasably fitted together via, e.g.,friction fit press fit, twist fit, snap fit, over-molding or molding,thermal bonding, and/or welding. Additionally or alternatively, upperhousing 900 and lower housing 910 may be fixedly fitted together, forexample, via an adhesive or a screw mechanism. Fan 930 may be placed orinstalled inside lower housing 910.

FIGS. 10A-10C illustrate exemplary embodiments of lid 218 having fan 930installed inside lower housing 910. As shown in FIGS. 10A-10C, lowerhousing 910 may have a chamber 911. Chamber 911 may have a shape and/orperimeter substantially similar to that of an outside frame of fan 930such that fan 930 may be held in chamber 911. Lower housing 910 mayinclude a plurality of air holes 912 that allow airflows havingincreased velocities caused by fan 930 to enter chamber 210 to causeand/or increase a turbulence of the air in chamber 210. A wall having aplurality of ridges 913 at the top may surround chamber 911. As shown inFIG. 10B, in some embodiments, lower housing 910 may also include one ormore projections 918 for fitting with upper housing 900.

Fan 930 may be a mechanical fan, a piezoelectric fan, an electric fan, amechanical-electric fan, a diaphragm fan, or any suitable type of fanthat may generate turbulence of air, such as a brushless DC cooling fan.A brushless DC cooling fan may include a brushless motor that providesthe torque, force, and/or moment driving the fan. Brushless motors maynot have any mechanical brush contacts with the commutator, i.e., themoving part of a rotary electrical switch, which may reduce theprobability of discharging electrons and/or generating electric sparksin mist 104. Thus, in some embodiments, fan 930 is a brushless DCcooling fan, which may increase the safety of using fan 930 in chamber210 filled with mist 104, e.g., a mist 104 generated from liquid 322containing a flammable solvent.

During the processing of object 100, fan 930 may operate to createand/or increase the amount of turbulence of the air in chamber 210 toreduce the temperature gradient and increase the distribution of themicro droplets of mist 104. However, it is contemplated that constantstirring and/or substantially increasing the velocity of the movement ofthe air and the micro droplets of mist 104 in chamber 210 may have oneor more effects on the micro droplets. For example, the increasedturbulence and/or velocity of the air in chamber 210 may increase theevaporation of the micro droplets in chamber 210. For another example,the increased turbulence and/or velocity of the air in chamber 210 mayincrease the moving, pushing, and or driving of micro droplets of mist104 to the walls of chamber 210, where they may then accumulate and flowtowards plate 224. Such effects may reduce the amount of micro dropletsof mist 104 generated by nebulizer 212, e.g., nebulizer assembly 730,and may affect the smoothing and/or processing of object 100.

It is also contemplated that the effects of fan 930 on the microdroplets of mist 104 may depend on the speed and/or the amount of timefan 930 operates, which may be adjusted or controlled by a drivercircuit, control circuits 217, and/or user control 211, for example, toachieve a satisfactory distribution of the micro droplets of mist 104.In some embodiments, the speed of fan 930 may be adjusted and/or reducedby using pulse-width modulating, e.g., modulating the width of a pulsedvoltage or current supplied to the fan. Additionally or alternatively,fan 930 may be operated intermittently, e.g., pulsing the operation offan 930 by switching on and off of its power supply. The period of timefor one continuous operation of fan 930 may range from about 1 second toa few seconds, from about a few seconds to about 10 seconds, or fromabout 10 seconds to less than a minute. The interval between each pulsedoperation of fan 930 may range from a few seconds to about tens ofseconds, from a few seconds to about 1 minute, or from about 1 minute toa few minutes, or longer. During the interval between the pulsedoperations of fan 930, nebulizer 212 may generate mist 104, and theamount of micro droplets of mist 104 may be increased in chamber 210,and the micro droplets may be accumulated. During the period of theoperation of fan 930. The amount of turbulence of the air in chamber 210may be increased and the uniformity of the distribution of the microdroplets of mist 104 may then be increased. In some embodiments thedistribution of the micro droplets of mist 104 may be substantiallyuniform during or at the end of an operation of fan 930. The on-and-offoperation of fan 930 may be repeated by as many times as needed for theprocessing of object 100.

It is further contemplated that fan 930 may be used to substantiallyreduce the amount of micro droplets of mist 104 in chamber 210 after theprocessing of object 100. For example, fan 930 may be operated at a fullspeed for a period of time, ranging from a few seconds to a few minutes,to clear or purge mist 104. Such a clearing or purging operation mayallow object 100 and the smoothness of the surface of object 100 to beobserved, and/or may create an interesting effect of revealing object100 after the processing of object 100 is completed. Such clearing orpurging operation may reduce the time for mist 104 to substantiallydisappear before object 100 is retrieved, and may thus reduce the totalamount of time for processing object 100. Such clearing or purgingoperation may also reduce the amount of mist 104 released out of chamber210 when lid 218 is open, and/or may reduce the flammability of the airinside chamber 210 when mist 104 is flammable, for example, mist 104generated from liquid 322 containing flammable substance.

In some embodiments, as shown in FIG. 10B, lid 218 may include one ormore light sources 922, e.g., LEDs or light bulbs, in upper housing 900to illuminate object 100 and/or mist 104. Upper housing 900 may have araised surface 902 and a light pipe or cover 920 may be placed on top ofraised surface 902. Light pipe or cover 920 may be transparent. In someembodiments, raised surface 902 may have one or more projections 908,each of which may fit into a hole in light pipe 920, to secure or fastenlight pipe 920 to raised surface 902. In some embodiments, light pipe920 and raised surface 902 may be releasably fitted together via, e.g.,friction fit, press fit, twist fit, snap fit, overmolding or molding,thermal bonding, and/or welding. Additionally or alternatively, lightpipe 920 and raised surface 902 may be fixedly fitted together, forexample, via an adhesive or a screw mechanism.

In some embodiments, light pipe 920 may have one or more lenses. Eachlens may be placed below a light source 922 to collimate the lightemitted from light source 922. The collimated light from light source922 may pass through an aperture 904 in raised surface 902 and anaperture 914 in lower housing 910. The number of apertures 904 andapertures 914 may be the same as that of light sources 922. Lightsources 922 may emit light of the same color or of different colors.Light sources 922 may be turned on or turned off at different stagesduring the processing of object 100. For example, light sources 922 maybe turned on at the start and/or the end of processing object 100, orduring the processing of object 100. The illumination of object 100and/or mist 104 by light sources 922 may add interesting and aestheticeffects of the processing as well as functional indication of theoperation of apparatus 200. The functional indication may include, forexample, providing visual signals to a user indicating the start or thecompletion of the processing of object 100 and/or alerting any problemsduring the processing of object 100, e.g., inadequate amount of liquid322 in chamber 216 or reservoir 324, or increased temperature in chamber210.

As shown in FIGS. 10B and 10C, in some embodiments, lid 218 may includea circuit board 940, e.g., a printed circuit board (PCB). Light sources922 and/or fan 930 may be electrically connected to circuit board 940.Circuit board 940 may be, for example, placed on top of light pipe 920in lid 218. In some embodiments, the operation of light sources 922and/or the operation of fan 930 may be adjusted or controlled by circuitboard 940. Circuit board 940 may be electrically connected to controlcircuits 217 and/or user control 211, for example, and may receiveelectrical signals from control circuits 217 and/or user control 211. Insome embodiments, control circuits 217 and/or user control 211 maycontrol the operation of light sources 922 and fan 930 to coordinatewith the operation of nebulizer 212. In one example, fan 930 may becontrolled by circuit board 940 and/or control circuits 217 to start tooperate upon or after the start of nebulizer 212. In another example,light sources 922 may be controlled by circuit board 940 and/or controlcircuits 217 to illuminate at the start of nebulizer 212 or whennebulizer 212 stops operation. In other embodiments, the operation oflight sources 922 and/or fan 930 may be adjusted or controlled byadjusting user control 211. For example, when user control 211 receivesan input, e.g., a setting to start nebulizer 212, circuit board 940 mayturn on fan 930 and/or light sources 922.

After object 100 has been processed or surrounded by the micro dropletsof mist 104, there may be some micro droplets condensed to some residualliquid 322 on the surface of object 100. In some embodiments, thisresidual liquid 322 may be removed by evaporation, or by drying usingradiant heat, forced air, a vacuum, or any other suitable method. Insome embodiments, fan 930 may be used to remove the residue liquid 322on object 100, e.g., by increasing the evaporation of the residue liquid322.

In some embodiments, the processing, e.g., polishing or smoothing, ofobject 100 by apparatus 200 may include the following steps 1 to 4. Step1 may include receiving object 100 into chamber 210. For example,fixture plate 214 may be moved upwards up to top cover 219 by liftingarm 228 and lifting plate 226. Object 100 may be received onto fixtureplate 214 and then be lowered and placed inside chamber 210 as fixtureplate 214 moves downwards with lifting arm 228 and lifting plate 226.Step 1 may include opening lid 218 before object 100 is received inchamber 210 and closing lid 218 afterwards. Step 1 may also includeplacing liquid 322 in chamber 216 or reservoir 324.

Step 2 may include surrounding object 100 with mist 104 for apredetermined period of time. Step 2 may include applying a sufficientamount of voltage and/or current to nebulizer 212 to generate microdroplets of mist 104 from liquid 322. Step 2 may also include operatingnebulizer 212 in a continuous and/or an intermittent mode to increasethe uniformity of the distribution of the micro droplets of mist 104 inchamber 210 and/or surrounding object 100. Additionally oralternatively, step 2 may Include increasing the uniformity of thedistribution of micro droplets by increasing the turbulence of the airin chamber 210 using an air-agitating device, for example, fan 930.

The predetermined period of time for step 2 or the operation ofnebulizer 212 may vary depending on various factors, including, forexample, the size of object 100, the size of chamber 210, the number ofnebulizers 212 used, the amount and/or density of mist 104 generated bynebulizer 212, the environmental temperature in chamber 210, the type ofmaterial of object 100, the level of roughness or size of the ridgesalong the surface of object 100, and the type and/or composition ofliquid 322 used to generate the micro droplets of mist 104. The totalperiod of time for the operation of nebulizer 212 or for surroundingobject 100 with the micro droplets of mist 104 ranges, for example, fromabout a few minutes to about 10 minutes, from about 10 minutes to about20 minutes, from about 20 to about 30 minutes, from about 30 to about 40minutes, from about 40 to about 50 minutes, from about 50 to about 60minutes, from about 10 to about 30 minutes, from about 10 to about 40minutes, from about 10 to about 50 minutes, from about 20 to about 40minutes, from about 20 to about 50 minutes, from about 20 to about 60minutes, from about 30 to about 50 minutes, from about 30 to about 60minutes, from about 40 to about 60 minutes, or from about 10 to about 60minutes. In other embodiments, any suitable period of time during whicha satisfactory surface roughness and/or smoothness of object 100 isachieved may be selected for the operation of nebulizer 212 or apparatus200.

Step 3 may include terminating nebulizer 212 from generating mist 104.Step 3 may also include clearing or purging mist 104 in chamber 210 toreveal object 100 in chamber 210. For example, step 3 may includeoperating fan 930 at a full speed for a period of time to substantiallyreduce the amount of micro droplets of mist 104 in chamber 210, whichmay reduce a waiting time for object 100 to be retrieved. Step 3 mayfurther include switching off fan 930 after the period of time forclearing or until mist 104 is substantially cleared. Step 3 may furtherinclude removing residue liquid 322 on the surface of object 100 byincreasing the evaporation of residue liquid 322 on object 100.

Step 4 may include presenting object 100 outside of chamber 210 forinspection and/or retrieval. For example, when the processing of object100 is completed or a smoothness of the surface of object 100 issatisfactory, fixture plate 214, lid 218, and lifting arm 228 may moveupwards, opening lid 218, raising object 100 and fixture plate 214, andthen presenting object 100 out of chamber 210. Step 4 may also includelowering fixture plate 214 and closing lid 218 after object 100 isremoved from fixture plate. In some embodiments, steps 1 to 4 of theprocessing of object 100 may be iterated as few as or as many times asneeded until a satisfactory roughness or smoothness of the surface ofobject 100 are achieved.

It is to be understood that the particular examples and embodiments setforth herein are non-limiting, and modifications to structures,dimensions, materials, and methodologies may be made without departingfrom the scope of the present teachings. It will be evident that variousmodifications and changes may be made without departing from the broaderspirit and scope of the disclosure as set forth in the claims thatfollow. The specification and drawings are accordingly to be regarded asillustrative rather than restrictive.

What is claimed is:
 1. A method for smoothing a surface of an additivemanufactured object, the method comprising: receiving the object in achamber; generating a mist into the chamber by a nebulizer assembly froma liquid held in a reservoir, the mist comprising micro-droplets of theliquid; and surrounding the object with the mist, the mist interactingwith the surface of the object so as to improve smoothness of the objectsurface; wherein the nebulizer assembly comprises a mesh, a wick havinga distal end submerged in the liquid, and a vibrating element causingthe mesh to generate the mist from the liquid approximately at roomtemperature and without substantially vaporizing the liquid; and whereinthe liquid comprises at least one solvent selected from alcohols,ethers, esters, and ketones.
 2. The method of claim 1, furthercomprising making the object by an additive manufacturing techniqueusing at least one thermoplastic polymer.
 3. The method of claim 2,wherein the at least one thermoplastic polymer is selected from vinylacetal polymers, acrylonitrile-butadiene-styrene, poly (lactic acid),polycarbonate, polystyrene, polycaprolactone, polyamide and polyamidecopolymers, and cellulose based polymers.
 4. The method of claim 1,wherein the nebulizer assembly further comprises a driver circuitelectrically connected to the vibrating element.
 5. The method of claim4, further comprising operating the nebulizer assembly by controlcircuits comprising a memory and a processing circuit electricallyconnected to the driver circuit, wherein the memory stores a pluralityof instructions for the operation of the nebulizer assembly, and whereinthe processing circuit executes at least one of the instructions andsends electrical signals associated with the executed instructions tothe driver circuit.
 6. The method of claim 5, wherein the controlcircuits are electrically connected to a user control.
 7. The method ofclaim 1, wherein the mesh and the vibrating element form an integratedpart.
 8. The method of claim 1, wherein a plate is located between thechamber and the reservoir, and wherein the plate has at least oneopening and/or a concave surface configured to allow micro droplets ofthe mist to pass through.
 9. The method of claim 1, wherein the objectis received on a rotatable platform in the chamber, the method furthercomprising rotating the rotatable platform by a motor.
 10. The method ofclaim 1, wherein the nebulizer assembly further comprises a couplerplaced between the vibrating element and the wick, the couplertransporting the liquid from the wick to the mesh with limited orminimized impact on movement of the mesh caused by the vibratingelement.
 11. The method of claim 10, wherein the coupler and the wickare one integrated part.
 12. The method of claim 10, wherein the couplerand/or the wick are made of a material that does not substantiallydissolve in or react with the liquid.
 13. The method of claim 12,wherein the material of the coupler and/or the wick comprises aplurality of pores and/or channels.
 14. The method of claim 13, whereinthe material of the coupler and/or the wick is a soft, a compressible, acompliant, a squishy, a foam-like, a sponge, or a resiliently deformablematerial.
 15. The method of claim 1, wherein the mist comprises microdroplets whose diameters range from 5 μm to 100 μm.
 16. The method ofclaim 1, further comprising illuminating the mist and/or the objectusing a plurality of light sources.
 17. The method of claim 1, furthercomprising raising the object out of the chamber, and/or lowering theobject into the chamber using an automatic or a manual liftingmechanism.
 18. The method of claim 1, further comprising increasingmovement of air and/or micro droplets of the mist in the chamber usingan air-agitating device.
 19. The method of claim 1, further comprisinggenerating by the nebulizer assembly a continuous, intermittent, orpulsatile mist, or combinations thereof.
 20. The method of claim 1,wherein the liquid comprises water.